UK 19 February 2015 The battle between Labour's pluralists and tribalists will define its future The fragmentation of the UK party system is reawakening divisions on electoral reform. Jon Cruddas, the head of Labour's policy review, has declared his support for proportional representation. Photograph: Getty Images. Sign UpGet the New Statesman's Morning Call email. Sign-up Until recently it was possible to refer to "the three main parties" without fear of confusion. That began to change in 2013 when Ukip supplanted the Lib Dems in most opinion polls. With the rise of the SNP and the Greens, the picture has become even less clear. We still habitually refer to the Lib Dems as a "main party" but they now frequently poll behind their "smaller" counterparts. Many of their MPs privately believe that they will win fewer votes than Ukip at the general election; the most pessimistic fear a tussle with the Greens for fourth place. Britain is moving towards the fragmented, European-style party system that many thought impossible under first-past-the-post. It is the UK's majoritarian voting system that nevertheless means the House of Commons that is returned after 7 May will not reflect the epochal shifts in voting intention. Ukip may poll upwards of 10 per cent but win only a handful of seats (as Lord Ashcroft's latest survey suggests). The Lib Dems could poll below this level but retain around half of their 56 MPs. The Greens could poll five per cent but succeed only in returning Brighton's Caroline Lucas. (The SNP is notable as a small party whose well-concentrated support means it could break through the electoral walls of FPTP.) In this strange new landscape, divisions are emerging within Labour over how to respond. Jon Cruddas, the party's policy review head, and Sadiq Khan, the shadow justice secretary (and future London mayoral candidate), have recently declared their support for proportional representation to better reflect the public's preferences. Cruddas told the Guardian: "One of the things that is reflective of changes in me is, for example, proportional representation. That’s now not some sort of middle class indulgent exercise – it’s a fundamental issue in terms of democracy and people’s rights. I never had a view on it before; now I think it’s central to the rebuilding of the whole thing." In an interview with me last month, Khan, whose brief includes constitutional reform, said: "I’ve always been a PR supporter ... It means everyone has a stake in the outcome of the result. Rather than people having to vote tactically, they are voting knowing that they will have an effect on who wins the election. I meet too many people who vote for negative reasons, rather than for positive reasons. If we have a PR system it could, for example, lead to higher turnout. "I believe in us being citizens, rather than consumers, and one of the ways that people will turn from being consumers into citizens is thinking that their vote counts and that will lead to that active citizenship, rather than this passive consumerism that there is now." By contrast, in an interview with me in this week's NS, Michael Dugher, the shadow transport secretary, hails the retention of FPTP in the 2011 referendum and denounces those in Labour who advocate "cosying up" to the Lib Dems. "Actually, minority governments, coalitions are pretty rare in our system," he said. "Not least thanks to the great virtues that are encapsulated by the first-past-the-post system and the very sensible decision to keep that electoral system, so they’re pretty rare in British history. I’m not convinced by this idea that we’re somehow in a new era of minority and coalition governments." There is nothing new about the divisions within Labour over electoral reform. Indeed, no issue split the party more in this parliament than whether to adopt the Alternative Vote (albeit a non-proportional system). But the divide between tribalists and pluralists, much discussed in 2010, has been reawoken by the fragmentation of the party system. According to one conception, Labour's future lies in acting as the head of a broad progressive movment, governing in partnership with the Lib Dems and the Greens. According to another, it remains the only legitimate vehicle for left-wing politics and should fight tooth and nail to retain the FPTP system that makes future majorities possible. In the days that follow the general election (now almost certain to result in another hung parliament), this division will take on greater significance. Should Labour (if elected) enter coalition with the Lib Dems or should it seek to govern alone? Where should it stand on future electoral reform? Is Labour part of a movement or is it the movement? The battle for supremacy between the party's tribalists and its pluralists will define the left's future. › The clash of data and the battle of statistics: why football management games are fun George Eaton is senior online editor of the New Statesman. Subscribe To stay on top of global affairs and enjoy even more international coverage subscribe for just £1 per month!